It might be technically possible or even trivial to fix the engine, but impossible for other reasons.
They are talking of licensing a new engine. If they licensed the current one, too, it might just be a matter of a vendor that went out of business or killed the product.
Not the engine author, but from our app experience:
Tracking Apple's breakage (in minor releases, even) and fixing our code -- code that was written to the defined API -- is a cost that is rising precipitously as Apple's quality and stability keeps going down.
If you have revenue from other platforms, it can make sense to just say "f it" and drop the platform. The AppStore is a shitty retail pipeline; 30% is a crazy commission for digital software distribution, the single-retailer-monopoly + appstore design is driving prices to unsustainable levels, etc.
